Cancer Odor Database (COD), a web-based database comprising comprehensive information of volatile organic metabolites of cancer (VOMC), known as cancer odor, which gives a structured overview of VOMCs that are of critical importance in cancer research. The database contains more than 1300 records with 19 critical features for each record, such as structural and chemical properties (e.g. boiling point, molecular formula and molecular weight) of 450 different VOMCs and their origins, which can be used effectively to identify correlations between VOMCs and various types of cancer.